Impact of pulsed field ablation on left atrial epicardial adipose tissue: a comparative study with cryoballoon ablation

Backgrounds

Left atrial epicardial adipose tissue (LA-EAT) is reported to associate with the atrial fibrillation (AF) recurrence after ablation. Pulsed field ablation (PFA) is known to cause less collateral damage compared with thermal ablation; however, its impact on adipose tissue remains unclear.

Purpose

To compare changes in left atrial epicardial adipose tissue (LA-EAT) after pulsed-field ablation (PFA) with those observed after conventional thermal ablation using a cryoballoon.

Methods

We retrospectively analyzed patients undergoing a first atrial fibrillation ablation at our institution who had both pre-procedural and post-procedural left atrial CT imaging within 6 months and next-day troponin measurements. Seventy-five PFA and 145 cryoballoon. cases were screened. To adjust for baseline LA fat volume and post-procedural changes, propensity-score matching was performed using age, AF type, CHADS2 score, dyslipidemia, pre-procedural LA-EAT volume, AF recurrence at the time of CT, and the interval between CT scans. Changes in hs-troponin I and LA-EAT were compared between matched PFA and cryoballoon. cohorts.

Results

A total of 70 patients (35 per group) were included in the matched analysis (mean age 66.1±9.7 years; 48 men; LAD 39.3±5.7 mm; paroxysmal AF 63 patients; CHADS2 1.1±1.0). In the PFA group, 24 procedures used circular catheter and 11 used pentaspline catheter.

Baseline LA-EAT volume was similar between groups (PFA 15.8±9.2 mL vs cryoballoon 15.7±7.3 mL; p=0.098; SMD 0.006). Baseline CT attenuation was also comparable (PFA 75.6±4.7 HU vs cryoballoon 74.9±5.1 HU; p=0.52). The mean interval between CT scans was 153.1±60.2 days. Eight patients in the PFA group and six in the cryoballoon group had AF recurrence, including blanking-period recurrences, at the time of the post-procedural CT scan.

The mean number of cryoballoon applications was 4.9±1.6 per case, whereas PFA required 51.7±13.2 applications per case; posterior wall isolation was performed in 18 PFA cases with a mean of 9.4±10.3 applications.

Hs-troponin I value were significantly higher after PFA (22,411.2±10,145.1 ng/L vs 12,546.2±4,881.0 ng/L; p<0.001) (Figure 1). Post-procedural LA-EAT volume was 14.3±8.8 mL in the PFA group and 12.3±6.3 mL in the cryoballoon. group (p=0.26). The reduction in LA-EAT was significantly smaller after PFA (1.43±2.62 mL vs 3.46±3.96 mL; p=0.014) (Figure 2).

Conclusions

Although PFA resulted in greater myocardial injury as reflected by higher troponin release, its impact on LA-EAT reduction was smaller compared with cryoballoon ablation.Figure 1Figure 2